Printing ink



Patented Apr. 8, 1924.

WILLIAM J. MoELR OY, OF NEW YORK, JOHN CLARKE, 0F MANHASSET, NEW YORK,

PATENT OFFICE.

ASSIGNORS, BY MESN'E ASSIGNMENTS, T0 ALCHEMIC GOLD COMPANY, INC., A COR-PORATION 015 NEW YORK.

No Drawing.

To all whom it may concern:

Be it known that we, WILLIAM J. McEn- ROY, a citizen of the UnitedStates, and a resident of the borough of Manhattan, city, county, andState'of New York, and JOHN CLARKE, a citizen of the United States, anda resident of the village of Manhasset, town of North Hempstead, countyof Nassau, and State of New York, have invented a new and usefulImprovement in Printing Inks, of which the following is a description,as well as of the manner and process of making, constructing,compounding, and using the same, in such full, clear, concise, and exactterms as to enable any person skilled in the art or science to which itappertains or with which it is most nearly connected to make, construct,compound, and use the same.

Our invention relates generally to printing inks and particularly tothose having metallic powders as their pigments.

The objects of our invention are the production of improved printinginks adapted for general use and more especially for use in embossingand die-printing upon bookcloth, leather and other materials commonlyused for book-casings; particular objects are the production of inks ofthis class which shall be adapted for application by a heated die, plateor other impression member, preheated to embossing temperatures, andwhich shall be characterized by the qualities of drying immediatelyunder the relatively high temperature preferred in embossing metallicpowders; and having properties of strongly adhering to and coveringsmoothly, evenly and completely the surface upon which they are stamped;of being rendered lustrous by the heat of the metal by which they areimpressed upon such object; of permanently retaining their originalcolor and luster without tarnishing or fading; of high boiling point andof low volatility.

Further objects are the provision of an ink with the foregoing qualitieswhich can be mixed ready for use by the manufacturer and which will notcorrode or otherwise deteriorate in the container, and which, whenpackaged, and transported shall remain in its original state with itsqualities and both its physical and chemical conditions unimpaired evenafter long lapse time.

PRINTING INK.

Application filed May 20, 1922. Serial No. 562,437.

ploying a vegetable wax as a binder for the metallic powders and asolvent for the hinder, but it has been found that the acidic solventsemployed caused the bronze powders to corrode; also that the acidsolvent vehicle evaporated quickly, leaving the residue a hardened massdiflicult to reclaim; and further, that the characters and patternsembossed or otherwise printed therewith rubbed or even flaked off.

It has also been proposed to employ a resin as a binder in lieu of wax,with a suitable solvent therefor. It has been found, however, that dueto the acid content of the resins, the metallic powders soon becamecorroded. These ingredients cannot, therefore, be combined by themanufacturer and sold as a ready-mixed ink. It is necessary to packagethe metallic pigment separately from the binder and its vehicle solventand to delay mixing them to form the ink desired until the printer isready to use it. This devolves upon the user a mixing operation which,by reason of the fine state of division of the metallic pigment,requires time, labor and skill to produce a homogeneous, correctlyproportioned ink of the right consistency.

Our invention attains the above recited features of advantage whileavoiding the disadvantages inherent in inks of the acidconstituent classdescribed.

With the foregoing desired objects in view and others hereina terdeveloped, our invention, broadly stated,.consists in the discovery of aprinting ink composed of metallio powders and a neutral binder dissolvedin a neutral solvent,which solvent ha a high boiling point and lowvolatility.

All resins are acid. Otherwise most of the resins possess qualitiesdesirable in a binder, articularly the capacity to coat or encasetie'comminuted particles composing the metallic pigments when printedand thereby protect the printed ink from discoloration by contact with,atmospheric gases. Of the rosins, white rosin is espeoially suitableexcept for the abietic acid constituting its normal major constituent,which renders it a bronze powder corrosive. By esterification of therosin with a glyceryl radical, the abietic acid is neutralized. Thisproduct is known commercially as ester gum. It is soluble in resinsolvents, though not itself a resin, and readily soluble in terpineol,which is also non-acid. Other resins and rosins may be similarly treatedto obtain their esters.

Most resin solvents have a boiling point so low that they cannot be usedwith a die heated to the temperature requisite to impart to the metallicpi ents the desired lustrous appearance burnished metal when stamped orembossed. Many of them are acid. Most of them have color. Terpineol isneutral as to acidity; is colorless; and has a sufficiently high boilingpoint to work satisfactorily at the temperatures desired to cause themetallic deposit to adhere firmly to the book-cover by fluxing the resinester, and by such fluxing to coat the metallic deposit with aprotective film thereof,

rendering it gas and waterproof, and to im part a maximum luster to thepigment. The comparatively low volatility of terpineol renders itadvantageous as a vehicle for the mixture of metallic powders anddissolved binder because the mixed ink retains its desired consistency,and will not cake or harden upon exposure. As an example of thepreferred proportions of the ingredients named:

Dissolve from to per cent by weight of ester gum in from 80 to 90 percent by weight of terpineol. Take two parts of bronze powder to one partof the gum solution, also by weight, and mix thoroughly.

The commercial purity of the ingredients varies somewhat. With theparticular grades of ingredients to be named, the proportions preferredare as follows:

With L. Hemmerdinger & Co.s Special No. 1 bronze powder, use Eimer &Amends terpineol, 84 per cent, and Charles F. Gledhills ester gum, 16per cent.

The compound, when mixed, is ready for use as an ink. It is of the usualconsis'tenc of printing inks, a pasty semi-liquid. t does not clog thetypes or dies and dries im- 1Ipeddiately under the heat of theimpression We have further found that the covering properties of thebronze powders are improved if re-enforced with a superlative gradethereof known commercially as lining. Lining is a bronze powder reducedto a finer stage of subdivision. For example, to 80 per cent of the Secial No. 1 bronze powder, above specific we add 20 per cent of lining,by weight, the binder and vehicle remaining unchanged inproportionalities.

The above mixture is adapted for use at the preferred embossingtemperature afforded by the high of the electric. heater attachmentsupplied with their standard presses of the Universal type by the JohnThomson Press & Manufacturing Company, approximately 500 Fahr., or withthe presses of the Markem Machine Company, as described in their patentto Putnam, No. 1,108,518, of August 25, 1914, for machine for embossingor marking leather.

It will be obvious to those skilled in the art that the termbronze-powders as herein employed comprehends all the metallic powdersused as pigments.

While we prefer the particular features of utility and advantageattained by working the described ink with a heated impression head, wedo not intend to be understood as limiting our novel ink thereto, sinceit is adapted for use as are the ordinary inks used in printing, andworks well when used cold upon paper and the like.

Having thus described the preferred embodiment of our invention and thebest method now known to us of producing the same, we claim:

1. A printing ink suitable for application with a heated die, composedof a resin ester, a neutral solvent and a metallic pigment.

2. A printing ink suitable for application with a heated die, composedof an'ester of rosin, a neutral solvent and a metallic pigment. I

3. A printing ink composed of an ester of white rosin, a neutral solventand a metallic pigment.

4:. A printing ink composed of a resin ester, terpineol and a metallicpigment.

5. A printing ink composed of an ester of rosin, terpinoel and ametallic pigment.

6. A printing ink composed of an ester of white rosin, terpineol and ametallic pigment.

7. A printing ink consisting of two parts of metallic pigment and onepart of a binder solution containing between 10 and 20 per cent of aneutralized resin and between 80 and per cent of a neutral solventtherefor, both by weight.

8. A printing ink consisting of two parts of bronze powder and one partof a binder solution containing 16 per cent of ester gum and 84 per centof terpineol, both by weight.

WILLIAM J. Menus-or. JOHN CLARKE.

